Basically the body is a furnace the more protein you put in the more fuel you add to the furnace. Now protein is necessary for muscle development but too much can be bad especially in hot weather. Also it can raise kidney and liver enzymes. Your dogs energy is greatly effected by fat content.
P.S. you have to look at digestible nutrients. All the nutrients in the world are useless if the body can't digest them.
X2....if your dog's stool is soft and there's a lot of it at each bowel movement....you're wasting dog food because they aren't digesting it. Stool should be dark, firm enough to roll around and not much of it from what I know. Just my opinion of course.
